Effects of climate change on spatial evolution of apple production in China

【Objective】As the world’s largest producer and consumer of apples, China’s apple industry has undergone significant spatial pattern changes in recent years under the backdrop of climate change, mainly characterized by the transfer and concentration of production areas. Understanding the key climatic factors influencing the spatial evolution of apple production is of great significance for optimizing production layout and ensuring sustainable development. This study aims to systematically analyze the spatial evolution pattern of China’s apple industry from 2003 to 2022, identify the main climatic drivers of its spatial evolution, and provide a scientific basis for policy-making and industrial planning. 【Methods】Taking 23 major apple-producing provinces (autonomous regions) in China as the research objects, using panel data from 2003 to 2022, and applying comprehensive spatial econometric models and statistical analysis methods, this study systematically explored the spatial agglomeration pattern of apple production and its influencing factors. The specific research methods included the following aspects: Firstly, in the spatial autocorrelation analysis part, the Moran’s I index was used to evaluate the spatial agglomeration characteristics of apple production, revealing the positive correlation relationship and changing trend of its spatial distribution. By calculating the global Moran index, the spatial correlation of China’s apple production was analyzed. At the same time, combined with the local Moran index (LISA), high-value clusters (H-H clusters) and low-value clusters (L-H clusters) were identified to fur-ther reveal the spatial heterogeneity between regions. Secondly, a two-way fixed effect model was constructed to quantify the impact of climatic factors (annual mean temperature, rainfall, frost days, hail days, and mean maximum temperature) on the spatial layout changes of apple production. Through model fitting, the contribution degree of each factor to the spatial evolution of apple production was determined, and regional differences were analyzed. Finally, the analysis of key climatic variables focused on two climatic factors, annual mean temperature and rainfall amount, to explore their impact on the spatial distribution of apple production. At the same time, by classifying different precipitation years (wet year, normal precipitation year, and dry year), the relationship between the spatial layout changes of apple production and precipitation was determined, thereby revealing that part of the water demand in the apple production process came from natural precipitation. Based on the above calculation results, ArcMap 10.8.1 and Origin 2024 software were used to visually analyze the spatial distribution characteristics of different major production areas, explore the differences in climatic conditions among regions, and provide a basis for formulating regional differentiated policies.【Results】(1) China’s apple industry presents a significant“agglomeration of superior production areas”feature. During the study period, the degree of spatial agglomeration as a whole showed a downward trend (Moran index decreased from 0.175 6 to 0.107 7), but an advantageous production area centered on Shanxi and its surrounding regions was formed. Shanxi Province has always maintained the H-H agglomeration type feature, indicating that the Loess Plateau Production Area has become the core agglomeration area of China’s apple industry. (2) The layout of apple production areas shows a clear“westward and northward expansion”trend. From 2003 to 2022, the suitable temperature area moved northwestward, and Xinjiang became a new suitable temperature area; while the traditional production areas in the North China Plain (Henan, Shandong, and Hebei) gradually transformed into sub-suitable or unsuitable areas due to the annual mean temperature rising above 15.4 ℃. The changes in the layout of the apple industry and the suitable temperature area are highly consistent. (3) The impact of climatic factors on the changes in apple production areas shows regional heterogeneity. Annual mean temperature, frost days, and mean maximum temperature have a key impact on the industrial layout; precipitation has a significant impact on the Bohai Bay production area and the Yellow River Ancient Course production area; both frost days and hail days have a negative significant impact on the characteristic production areas. (4) There are significant differences in production areas under different precipitation year. The Yellow River Ancient Course production area shows the best production performance in dry year; the Bohai Bay production area and the Loess Plateau production area show the best performance in wet year; the characteristic production areas and the Southwest Cold and Highland production areas show relatively small differences.【Conclusion】This study systematically reveals the spatial evolution pattern of China’s apple production and the influencing climatic factors under the background of climate change. Based on these research findings, the following suggestions are put forward: Strengthen the industrial construction in the core production areas of the Loess Plateau, and create a strong cluster and high-quality apple industrial belt; formulate differentiated apple cultivation plans according to the climatic characteristics of different production areas; establish and improve the meteorological disaster monitoring, early warning, and prevention and control system, especially for frost disasters.